#include "stdafx.h"
#include "glibconf.h"
#include "base64.h"
#include <iostream>

static const std::string base64_chars = 
             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
             "abcdefghijklmnopqrstuvwxyz"
             "0123456789+/";


static inline bool is_base64(unsigned char c) {
  return (isalnum(c) || (c == '+') || (c == '/'));
}

GString base64_encode(BYTE* bytes_to_encode, unsigned int in_len)
{
	GString ret;
	int i = 0;
	int j = 0;
	unsigned char char_array_3[3];
	unsigned char char_array_4[4];

	while (in_len--)
	{
		char_array_3[i++] = *(bytes_to_encode++);
		if (i == 3)
		{
			char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
			char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
			char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
			char_array_4[3] = char_array_3[2] & 0x3f;

			for(i = 0; (i <4) ; i++) ret += base64_chars[char_array_4[i]];
			i = 0;
		}
	}

	if (i)
	{
		for(j = i; j < 3; j++)
		char_array_3[j] = '\0';

		char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
		char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
		char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
		char_array_4[3] = char_array_3[2] & 0x3f;

		for (j = 0; (j < i + 1); j++) ret += base64_chars[char_array_4[j]];

		while((i++ < 3))
		ret += '=';
	}

	return ret;
}

void base64_decode(GString encoded_string, BYTE *ret)
{
	int in_len = (int)encoded_string.GetLength();
	int i = 0;
	int j = 0;
	int in_ = 0;
	int seek=0;
	unsigned char char_array_4[4], char_array_3[3];

	while (in_len-- && ( encoded_string[in_] != _T('=')) && is_base64((BYTE)encoded_string[in_]))
	{
		char_array_4[i++]=(BYTE)encoded_string.GetAt(in_);
		in_++;
		if (i ==4)
		{
			for (i = 0; i <4; i++) char_array_4[i] = (BYTE)base64_chars.find(char_array_4[i]);

			char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
			char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
			char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

			for (i = 0; (i < 3); i++)
			{
				ret[seek]= char_array_3[i];
				seek++;
			}
			i = 0;
		}
	}

	if (i)
	{
		for (j = i; j <4; j++) char_array_4[j] = 0;
		for (j = 0; j <4; j++) char_array_4[j] = (BYTE)base64_chars.find(char_array_4[j]);

		char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
		char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
		char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

		for (j = 0; (j < i - 1); j++)
		{
			ret[seek]=char_array_3[j];
			seek++;
		}
	}
}